Shape Optimization Of The Shell And Sensitivity Analysis Of Energy Consumption Of Argo Profiling Float

Argo profiling float is a new type of autonomous vehicle,which can drift freely in the ocean,realize the movement of diving and floating by adjusting its net buoyancy,and collect the parameters of sea water temperature,conductivity(salinity)and pressure based on the carried sensors.Argo profiling float has become an important ocean observation platform because of its advantages of low energy consumption,strong endurance,wide detection range,simple principle and low noise.In this paper,a 4000-meter deep sea self-sustaining intelligent Argo profiling float independently developed by the research group is taken as the research object,and the shell shape optimization,kinematic modeling,energy consumption and range parameter sensitivity analysis based on the Sobol' method are carried out,and a series of tests the profiling float are introduced.The main research results and innovations are as follows:1.In the shape optimization of the shell,the index of nose shape,the index of tail shape,the ratio of nose length to total length and the ratio of tail length to total length of the shell are selected as the design variables,and the resistance,mass and envelope volume of the shell are taken as the optimization objectives.The experiment design is carried out based on the optimal Latin hypercube method,and the response surface approximation model of the optimization objectives about the design variables is established with the test data.Based on the fast elitist Non-dominated Sorting Genetic Algorithm II(NSGA-II),a group of solutions are selected from the Pareto front as the final design scheme of the shell of the second-generation Argo profiling float.The feasibility of the scheme is verified by simulation and experiments.Finally,the influence law and degree of each design variable on the optimization objective are obtained through the main effect analysis.2.The kinematic and dynamic model of Argo under the influence of current is established.The inertial coordinate system,body coordinate system and velocity coordinate system are established,the relevant motion parameters are defined,and deduce the kinematic equations through the transformation between the coordinate systems;the force on the Argo is analyzed and the model of the whole profiling float is generalized.Based on the momentum theorem and laws of dynamics,the dynamic equations are derived by calculating the total kinetic energy of the Argo-water system.The motion model of the profiling float in the vertical plane is obtained by simplification,and the motion model of the profiling float under the steady-state motion in the vertical plane is obtained by further simplification.3.The single section motion flow of Argo is introduced.Based on the kinematic and dynamic model,the energy consumption of each subsystem in the single section is calculated respectively,and energy consumption model of the single section under the steady-state motion is obtained.According to the motion process and relevant parameters of the profiling float,the range model is derived.Through theoretical derivation,experimental verification and practical design requirements,the range and distribution of parameters for sensitivity analysis are determined.Based on Sobol's global sensitivity analysis method,the first-order sensitivity coefficient and total sensitivity coefficient of the energy consumption and range model in the single section are calculated,which point out the optimization direction for designers to reduce the energy consumption and improve the range of profiling floats in the design process.